• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1536-1540
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• 1996

The Design of are quenching parts of molded case circuit breakers depends on the utilization of strength and distribution of the magnetic field by which the arc is forced. The magnetic field causes the are to move into a set of V-slotted iron grids, where the are is extinguished rapidly. This paper present the effective method 10 design V-slotted iron plates of the are breaking chamber of molded case circuit breakers. This magnetic force was calculated by using the flux densities in the arc which are obtained by three dimensional finite element method, as a result of that this paper verified by testing that a grid model which has biggest magnetic force is excellent in the are quenching ability.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.355-356
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• 2008

현재 초고압 송변전기기에 적용되고 있는 $SF_6$ 가스는 절연 및 소호성능이 우수하며 회복특성이 뛰어나기 때문에 초고압 기기의 절연매체로서 일반적으로 사용하고 있다. 그렇지만 $SF_6$ 가스의 온난화 계수는 $CO_2$의 약 23,900배로 매우 높고, 대기 중으로 방출될 경우에는 온실효과 가스로 문제가 되고 있다. 따라서, $SF_6$ 가스의 대기 중에의 방출을 최대로 피하기 위해 단계별 연구가 필요하다. 본 논문에서는 초고압 전력기기의 DS/ES부에 Dry Air Gas와 절연코팅소재를 적용하여 절연특성에 대한 연구를 하였다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.3
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• pp.237-243
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• 1992

The large value of the snubber capacitor is needed to protect the devices in high voltage converters using series connected power semiconductors. But that results in more losses and longer commutation time. So, new technique of series connection is required, which can minimize the value of snubber capacitor and also promote the reliability of high voltage converters. We study on the switching characteristics of series connected power semiconductors and then propose a novel switching algorithm for series-connection which is able to implement not only the dynamic voltage balancing in spite of the differerce of switching characteristics, but the minimization of the value of snubber capacitor, through the change of the value of snubber capacitor by Miller effect. Finally, we illustrate the validity of this synchronization by computer simulation and experimental results.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1751-1753
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• 2002

Arc phenomena occur in the air, must be more diverse than vacuum and SF6. An air arc interruption method has been used in low rated voltage circuit breakers such as ACB, MCCB and MCB. Most of them have the arc chamber composed of arc chutes and lateral walls that made of many kinds of materials. Therefore, the criterion of material selection is necessary for breaking capacity improvement. So, we selected some contact and lateral wall materials, and carried out short circuit tests. Especially, some parameters of arc plasma properties were very different each polymeric wall material.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.12-14
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• 2002

In this paper, magnetic force on acting arc was analyzed by 3-D FEM for three DC arc-quenching rooms having different magnetic flux paths. We measured arc breaking time in prototypes by experiment so that we compared the relation of magnetic force and arc breaking time. Finally, we present the techniques for magnetically-driven arc and for the prediction of arc breaking time.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.900-902
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• 1999

This paper deals with the interrupting characteristics of fuses element in different media of arc extinguisher. Aluminum hydro-oxide, boron nitride, silica and there size have been investigated here for their prospects as filling media in heavy current, high breaking capacity fuses. The result of these study are compared with those on silica sand at high current. This study demonstrates that silica sand is far superior filler in fuses for heavy current interrupting then the compound tested.

• Progress in Superconductivity
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• v.12 no.1
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• pp.23-26
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• 2010

A double line commutation (DLC) type SFCL with first peak limiting function has been proposed for ideal fault current limiting operation. Very fast switching (commutation) without any arc or high voltage problems for any kind of switching device is needed for the first peak current limiting. We've tried to find suitable conditions for a successful switching of a Vacuum Interrupter (VI) with HTS elements as a Peak Current limiting Resistance (PCR).

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.44-46
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• 2001

This paper describes the use of the PHOENICS CFD package for the simulation of the high-current period of the arcing process in a hybrid rotating arc/auto expansion by interrupter. The operating principle of this device depends on rapid arc rotation due to the magnetic field created by the fault current through a coil which is mounted on contacts and also relies on the principle of thermal expansion created by arc energy in extinguishing chamber and finally causes pressure rise in expansion volume. This paper is divided into three main sections. The first gives a brief overview of the interrupter. The second section gives a full description of the methods used in the calculation. The final section presents some sample results for the hybrid interrupter.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.05c
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• pp.51-54
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• 2001

This Paper is described basic principles of arc quenching in Molded Case Circuit Breaker. We analyzed magnetic blowout forces acting on the arc in contact system when circuit breakers interrupt fault currents in different three models by 3-D FEM(Finite Element Method). The interrupting time simulated is compared with that of short circuit tests. The results of this study derive valid of the simulation method and present the techniques to improve arc quenching performance.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1255-1256
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• 2006

전력 계통에서 과전류가 발생하게 되면 이것을 차단하기 위해 차단기가 동작한다. 차단기가 동작하게 되면 기계적으로 전기의 흐름을 단절시키므로 아크 현상이 발생한다. 이때 차단기의 차단 절차를 이해하기 위해서는 아크 현상의 모델링이 필요하다. 특히 포스트 아크 현상에 관한 정밀한 모델링이 이루어질 경우 차단기에서의 소호 특성을 파악하기 용이하다. 우리는 이 논문에서 전력 계통의 과도현상 분석 수치해석 프로그램인 EMTP(Electro-Magnetic Transient Program)를 이용하여 아크 현상에서 발견되는 포스트 아크 전류(Post-Arc Current) 및 TRV(Transient Recovery Voltage)를 반영하는 아크 모델을 설계하였다.